From the Hebrew name אֱלִיָּהוּ ('Eliyyahu) meaning "my God is Yahweh". Elijah was a Hebrew prophet and miracle worker, as told in the two Books of Kings in the Old Testament. He was active in the 9th century BC during the reign of King Ahab of Israel and his Phoenician-born queen Jezebel. Elijah confronted the king and queen over their idolatry of the Canaanite god Ba'al and other wicked deeds. At the end of his life he was carried to heaven in a chariot of fire, and was succeeded by Elisha. In the New Testament, Elijah and Moses appear next to Jesus when he is transfigured.
Because Elijah was a popular figure in medieval tales, and because his name was borne by a few early saints (who are usually known by the Latin form Elias), the name came into general use during the Middle Ages. In medieval England it was usually spelled Elis. It died out there by the 16th century, but it was revived by the Puritans in the form Elijah after the Protestant Reformation.